Basic Math

4Rager

4Rager

New member
I finally got confirmation that the rest of the parts for my lift should be arriving tomorrow, so I was visualizing how everything would be installed and thought of something that made me laugh.

1. The rear diff is the lowest point of ground clearance. 2. A 3" suspension lift has no impact on the rear axle. 3. Therefore the only ground clearance you gain is equal to half of your tire size increase.

For me that's going from 31.6" stock to 32.7" (285/70r17 KO2), therefore I will only gain ~.5" of ground clearance. For the people that really wheel, it's clear why only being able to fit a 33 without major mods is so disappointing. Either way, I'm not any less excited to get started on my build.
 
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This math logic only applies in situations like soft sand or mud where the primary danger is burying the tires and having the rear axle bottom out and drag. I grew up in a mud area (central Mississippi), and I'm quite familiar with this issue.

In those situations, you are correct, tire diameter (and width) controls. Lifts are primarily for looks and the ability to fit bigger tires.

But in boulders and rock ledges you can (or should) vary your line to miss the center diff. Gaining a few inches of frame/skid plate clearance as well as improvements in approach and break angles through a lift can make a HUGE difference. Gaining tire articulation and/or disconnecting sway bars (or using KDSS) can do a better job of keeping all four tires on the ground and pulling.

I currently live in the rocks of southeast Tennesse and I'm having to learn all new things about off-roading.
 
No offense but with all the recent threads... I thought you were going to argue that we all only have 2x2 trucks because real 4x4s have 16 wheels. Whelp, I was wrong!
 
I believe they are more or less the same, but for models equipped with KDSS, the front skid plate is technically the lowest.
 
jwkilgore said:
This math logic only applies in situations like soft sand or mud where the primary danger is burying the tires and having the rear axle bottom out and drag. I grew up in a mud area (central Mississippi), and I'm quite familiar with this issue.

In those situations, you are correct, tire diameter (and width) controls. Lifts are primarily for looks and the ability to fit bigger tires.

But in boulders and rock ledges you can (or should) vary your line to miss the center diff. Gaining a few inches of frame/skid plate clearance as well as improvements in approach and break angles through a lift can make a HUGE difference. Gaining tire articulation and/or disconnecting sway bars (or using KDSS) can do a better job of keeping all four tires on the ground and pulling.

I currently live in the rocks of southeast Tennesse and I'm having to learn all new things about off-roading.
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This is 100% accurate. Approach/departure/breakover numbers are way more important than axle clearance when you're articulating through rocks or big ruts.
 
Keith_PDX said:
Appalachian Mountain People can do math? I digress, humanity is evolving.

;)
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bimrunner said:
They can count to about 8 I believe. Once they run out of fingers and toes, they start counting teeth. Yeah... 8 seems to be average out there.
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Toothpaste was invented here on this mountain top. If it was invented anywhere else it would have been called teethpaste. I married my cousin. My father is also my half brother. Our family tree is a stick....

It's pretty funny when I show up in New York or LA. Stereotypes can be broken lol.
 
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Appalachian Mountain People

Jhalko said:
Who doesn't like a good hoedown and banjo music?

West coast Snobs!
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Hey, I resemble that remark! California born and raised. We're such snobs out here that no one ever drives their Range Rovers off-road. Might get the body dirty. :loco:

Riddle me this:

Father and son are timbering in the Appalachian Mountains. Father accidentally chops off two of his son's fingers swinging an axe. The pick up the digits (they can count to two and get both) and rush off to the hospital. When they walk into the emergency ward the doctor comes out and says, "I can't operate on this man. He's my son".

Who is the doctor?

Hint: Greg's family tree is a stick.
 
DesertCanyons said:
Hey, I resemble that remark! California born and raised. We're such snobs out here that no one ever drives their Range Rovers off-road. Might get the body dirty. :loco:

Riddle me this:

Father and son are timbering in the Appalachian Mountains. Father accidentally chops off two of his son's fingers swinging an axe. The pick up the digits (they can count to two and get both) and rush off to the hospital. When they walk into the emergency ward the doctor comes out and says, "I can't operate on this man. He's my son".

Who is the doctor?

Hint: Greg's family tree is a stick.
Click to expand...

Why are they using an axe? That's the real question. :beer:
 
4Rager said:
1. The rear diff is the lowest point of ground clearance. 2. A 3" suspension lift has no impact on the rear axle. 3. Therefore the only ground clearance you gain is equal to half of your tire size increase.
Click to expand...

The rear diff clearance is relative to your tires. So, when your tires are on a an obstacle the diff goes right up with it.

Ground clearance of the diff does become an unavoidable issue in some situations, but it is not near as big of a deal as approach, break-over and departure. The lift will have a very positive impact on those aspects.

An experienced driver will always pick lines with the rear diff in mind. Angle of attack on big ledges... is critical.

Bigger tires are mainly for improved traction via contact patch length and roll over angle. The added ground clearance is just a bonus.

Go ride a mountain bike with 26" wheels at slow speeds over a few rocks obstacles without manualling up the front end. Now try the same on one with 29" tires. The difference is significant and will quickly make you realize how tire diameter impacts capability of an offroad vehicle with a heavy front end that can't be easily throttled or weight transferred up and over.
 
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DesertCanyons said:
Hey, I resemble that remark! California born and raised. We're such snobs out here that no one ever drives their Range Rovers off-road. Might get the body dirty. :loco:

Riddle me this:

Father and son are timbering in the Appalachian Mountains. Father accidentally chops off two of his son's fingers swinging an axe. The pick up the digits (they can count to two and get both) and rush off to the hospital. When they walk into the emergency ward the doctor comes out and says, "I can't operate on this man. He's my son".

Who is the doctor?

Hint: Greg's family tree is a stick.
Click to expand...

The doctor is his mom

When someone yells Hoedown here in south Georgia all the women fall on the floor.......
 
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